fix problems with file mounts in Docker containers

Author: alalek

deploy.sh

@@ -30,9 +30,9 @@ ALLOW_STOP=0 # Use Web UI or allow "docker stop <container>"
 HTTP_PORT=\${HTTP_PORT:-8010}
 SLAVE_PORT=\${SLAVE_PORT:-9989}
 
-OPTS="\$DOCKER_OPTS --name \${CONTAINER}"
-
-[[ -z \$CONTAINER_HOSTNAME ]] || OPTS="\$OPTS --hostname \$CONTAINER_HOSTNAME"
+. docker_utils.sh  # updates OPTS variable
+docker_mount_add credentials/htpasswd /etc/buildbot/htpasswd ro
+docker_mount_finalize || exit 1
 
 create_container() {
   docker create -it \\
@@ -41,7 +41,6 @@ create_container() {
     -p \${SLAVE_PORT}:9989 \\
     -v \${P}:/app \\
     -v \${P}_data/master:/data \\
-    -v \${P}/credentials/htpasswd:/etc/buildbot/htpasswd:ro \\
     \${IMAGE}
 }
 EOF

docker_utils.sh

@@ -0,0 +1,40 @@
+# Don't use this as a standalone script
+
+OPTS="$DOCKER_OPTS --name ${CONTAINER}"
+[[ -z $CONTAINER_HOSTNAME ]] || OPTS="$OPTS --hostname $CONTAINER_HOSTNAME"
+
+# Reset file
+echo "#!/bin/bash" > ".update_docker_mount.sh"
+chmod +x ".update_docker_mount.sh"
+
+# There are several issues with mounting of configuration files into container.
+# One of them is related to files "update" problem with live container (without container re-creation).
+# Tools (ansible, vim) usually creates new file and then rename it "atomically" (this assigns new "inode" to file).
+# Docker binds "inode", not a file name, so that changes are not updated in the container.
+# Workaround is mounting file "clones" instead of original files.
+docker_mount_add()
+{
+  SRC="${P}/$1"
+  DST=$2
+  if [[ "x$DST" == "x" ]]; then
+    DST="/opt/pullrequest/$1"
+  fi
+  MODE=${3}
+  if [[ "x$MODE" != "x" ]]; then
+    MODE=":${MODE}"
+  fi
+
+  if [[ -f "$SRC" ]]; then
+    DOCKER_SRC="${P}/.docker/$1"
+    DIR=$(dirname "${DOCKER_SRC}")
+    echo "mkdir -p $DIR" >> ".update_docker_mount.sh"
+    echo "cp -p \"$SRC\" \"${DOCKER_SRC}\"" >> ".update_docker_mount.sh"
+    SRC="${DOCKER_SRC}"
+  fi
+  OPTS="$OPTS -v ${SRC}:${DST}${MODE}"
+}
+
+docker_mount_finalize()
+{
+  . .update_docker_mount.sh || exit 1
+}